Advanced Design. The taillight has a built-in 330mAh rechargeable lithium battery. It comes with a charging cable and can be charged via computer, power bank, or any device with a USB interface. Four Lighting Modes: The taillight uses a one-touch switch and offers four different lighting modes to meet your individual needs, including full brightness, half brightness, fast flashing, and slow flashing. Easy Installation: It can be easily slid in or out of the mounting bracket with a simple push, without removing the entire mounting bracket. This silicone strap for taillight mounting is designed with four openings for a snug fit on most handlebars and seat posts. Riding Safety: This taillight emits a bright, wide-angle beam that can be seen several blocks away, so you don't have to worry about being hit by other vehicles. Buy with Confidence: Ascher is committed to providing high-quality products to its customers, and we strive to ensure your complete satisfaction. If you have any questions, please contact us, and we will resolve them for you as soon as possible.